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Group B streptococcal infection

Last reviewed: 30 Oct 2023
Last updated: 18 Nov 2022



History and exam

Key diagnostic factors

  • fever
  • symptoms of meningitis
  • signs of meningitis
  • symptoms of sepsis
  • signs of sepsis
  • symptoms of pneumonia
  • signs of pneumonia
  • symptoms of urinary tract infection
  • signs of urinary tract infection
  • symptoms of cellulitis
  • signs of cellulitis
  • symptoms of septic arthritis
  • signs of septic arthritis
  • symptoms of conjunctivitis
  • symptoms of sinusitis
  • signs of sinusitis
  • symptoms of otitis media
  • signs of otitis media
  • symptoms of endometritis
  • signs of endometritis
  • signs of chorioamnionitis
More key diagnostic factors

Other diagnostic factors

  • nonspecific signs of infection in neonate
  • nonspecific signs of infection in older patients
  • symptoms of intra-abdominal infection
  • signs of intra-abdominal infection
  • midgestation abortion or preterm labor
Other diagnostic factors

Risk factors

  • 0 to 7 days of age
  • maternal fever during labor
  • premature rupture of membranes (PROM)
  • previous baby with GBS disease
  • maternal GBS colonization
  • GBS bacteriuria during pregnancy
  • preterm delivery (<37 weeks)
  • low birth weight (<2500 g)
  • deficient maternal-specific IgG at term
  • twin sibling with GBS disease
  • maternal age <20 years
  • chorioamnionitis
  • age >60 years
  • pregnancy
  • multiparity
  • diabetes
  • obesity
  • advanced hepatic disease
  • renal disease
  • presence of central venous catheter
  • urologic disorders
  • break in skin integrity or skin ulcers
  • neurologic disease
  • immunosuppression
  • nursing-home resident
  • black or Hispanic race
  • malignancy
  • obstetric manipulation
  • presence of urinary catheter
  • HIV infection
  • trauma
  • asthma
  • consumption of placenta capsules
More risk factors

Diagnostic investigations

1st investigations to order

  • CBC
  • BUN
  • serum electrolytes
  • serum glucose
  • coagulation studies
  • LFTs
  • C-reactive protein (CRP)
  • blood culture
  • cerebrospinal fluid (CSF) Gram stain
  • CSF culture
  • CSF cell count and differential
  • CSF glucose and protein
  • antigen detection in CSF
  • Gram stain and culture of other sterile body fluids
  • chest x-ray
  • plain joint and/or bone x-ray
  • CT head
More 1st investigations to order

Investigations to consider

  • echocardiography
  • MRI
More investigations to consider

Treatment algorithm


early- or late-onset confirmed GBS neonatal infection (0-89 days of age)

infants and children

adults: nonpregnant

adults: pregnant and postpartum



Brendan Healy, MBChB, BSc (Hons), MRCP, FRCPath

Consultant in Microbiology and Infectious Diseases

University Hospital of Wales




BH has received honorarium and has been reimbursed for attending conferences from AbbVie (hepatitis C), Gilead Sciences (hepatitis C), Bristol Myers Squibb (hepatitis C), and Tillotts Pharma (fidaxomicin). BH declares that he has no competing interests in relation to the work carried out for this topic review, Group B streptococcus.


Dr Brendan Healy would like to gratefully acknowledge Dr Susannah Froude and Dr Harriet Hughes, previous contributors to this topic. We would also like to gratefully acknowledge Dr Benjamin D. Lorenz for his contributions to this topic.


SF declares that she has no competing interests. HH declares that she has received funds from Gilead and Biocomposites related to conference registration, travel, accommodation, and speaker fees.

Peer reviewers

William A. Petri, Jr, MD, PhD, FACP

Chief and Professor of Medicine

Division of Infectious Diseases and International Health

University of Virginia Health System




WAP declares that he has no competing interests.

James R. Hanley, MD, FAAP

Attending Physician

Pediatric Emergency Medicine

Ochsner Foundation Hospital

New Orleans



JRH declares that he has ownership of a limited amount of stock in various pharmaceutical companies, although no significant amounts of any company.

Kirsty Le Doare, BA, MBBS, MSc, PhD, FRCPCH

Professor of Vaccinology and Immunology

St George's, University of London




KLD declares that their institution has received funds for GBS vaccine clinical trials; she has not received personal funds.

  • Group B streptococcal infection images
  • Differentials

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    • Endocarditis caused by other organisms
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  • Guidelines

    • Guidelines for the detection and identification of group B streptococcus
    • Prevention of early-onset group B streptococcal disease in newborns
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  • Patient leaflets

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